COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Boeing 767 Series Aeroplanes AD/B767/31 EEC System Electromagnetic Shielding 1/90 Applicability: As detailed in the Requirement Document. Requirement: Action in accordance with Boeing SB 767-71-0041 R2 or later revision. Note: FAA AD 89-21-04 refers. Compliance: Prior to 25 April 1991. Background: Boeing have advised that at the maximum probable lightning threat level, lightning induced voltage transients in excess of the EEC qualification requirement may result. A lightning strike at take-off could therefore adversely affect EEC operation and could result in uncommanded thrust loss greater than the loss of one engine.